Seven-month-olds' Discrimination of Statements and Questions

Distinguishing between statements and questions is an important ability for language learners. In English and many other languages, questions generally involve syntactic structures and word order patterns that are different from statements. For example, in English, questions often begin with whwords (e.g. who, what, where, etc.) and auxiliary verbs switch positions with subjects (compare I see Jim with Who do I see?). Distinguishing statements and questions is thus critical for learning the grammatical properties of the two sentence types. More broadly, the ability of learners to distinguish utterance types is required and assumed by many acquisition theories in which grammatical analyses are first carried out on canonical structures, such as simple transitive, declarative sentences (Pinker, 1984). Since questions and statements each account for a substantial portion of infant and child directed speech (44% and 30% respectively; Newport, 1977), learners’ ability to differentiate utterance types in their input is critical for analyzing the majority of utterances in the appropriate way. Yet, although many language acquisition theories assume that learners can differentiate these sentence types in the early stages of syntax acquisition, there is little evidence of how and when they do so. One potential source of sentence type information is prosodic information. In English and many other languages, there is evidence that adult listeners rely on pitch information as an important perceptual cue for distinguishing statements and questions. For example, although Russian has whwords, sentences often do not include lexical or syntactic/grammatical indicators of sentence type (Makarova, 2007). Russian has relatively free word order and no auxiliary verbs (Rojina, 2004) so listeners rely on pitch peak alignment rather than lexical cues to perceive distinctions between statements and yes/no questions (Makarova, 2007; Svetozarova, 1998). Statements and exclamations have earlier peaks than questions. There is also an effect of pitch peak height, where questions have higher pitch peaks than statements. In languages like English (Cruttenden, 1986, Lieberman, 1967) and French (Vion & Colas, 2006), which do use lexical markings (e.g. auxiliary verbs) to distinguish sentence types, the final pitch contour is a critical region in the utterance for perceiving distinctions between questions and statements. Săfárŏvá and Swerts (2004)